Vue3: Don't assign values to all slots (rollback to v7.0.27)

[kasperpeulen]

Closes #23668

What I did

I rolled back the slots version to v7.0.27.
The > v7.1 version assigned slots values even when they were not listed as args.

How to test

Let's check if our chromatic snapshots keep working.

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli/src/sandbox-templates.ts
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "build", "documentation", "maintenance", "dependencies", "other"]

🦋 Canary release

This pull request has been released as version 0.0.0-pr-23697-sha-615db423. Install it by pinning all your Storybook dependencies to that version.

More information

Published version	0.0.0-pr-23697-sha-615db423
Triggered by	@kasperpeulen
Repository	storybookjs/storybook
Branch	kasper/vue3-slots
Commit	615db423
Datetime	Thu Aug 3 08:46:56 UTC 2023 (1691052416)
Workflow run	5748593695

To request a new release of this pull request, mention the @storybookjs/core team.

core team members can create a new canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=23697

[shilman]

On my phone but if this is purely reverting a change and you have a good way to test it, I'm good with the change